TC-5021 & TC-5022 Product and Application Trainingcasmoon.com/upfile/file/20141020/2014102020293784551.pdf · Dow Corning . . . We Help You Invent The Future.™ TC-5021 & TC-5022

Dow Corning . . . We Help You Invent The Future.™

TC-5021 & TC-5022 Product and Application Training

August, 2005


• Thermally Conductive Greases• TC-5021/TC-5022 Properties and Design

Considerations• Process – Screen Printing• Testing - How Customers Evaluate Grease

Content


Thermally Conductive Greases


Thermal Interface Materials• Function

– To enhance heat transfer across the interface between a heat source and heatsink

• Characteristics– High thermal conductivity– Easy to process and apply– Usually electrically isolating– Often reworkable/bondable– Maintain properties

• Types of Interface Materials– Grease– Adhesives– Phase Change– Gel– Pads– Films– Tapes

• Market driven by growth of semiconductor devices that require thermal management (>2W power dissipation)


DCC Thermally Conductive Compounds

TC-5021, TC-5121, TC-5022

SE-4490CVPastes

SC4476CV, SC4477CV

SC4471CVSC-102,CN-8870

340, SH-340Greases

>2.52.0-2.51.5-2.01.0-1.50.5- 1.00.2-0.5

Thermal Conductivity (W/mK)


TIM 2 Application

Flip Chip BGA

LidLid Seal

Substrate

TIM 2Heat Sink

Flip ChipTIM 1


Intel CPU Power Consumption Trend

0

20

40

60

80

100

120

140

TDP

(Wat

t)

386486586Pentium ProPentium IIPentium IIIPentium IVPentium D


TC-5021/TC-5022 Properties and Design Considerations


Positioning and Value

TC-5022• 10-15% Better Thermal

Performance• Excellent Value Performance

Superior Reliability Performance

TC-5021• Comparable Performance &

Lower Price• Excellent Reliability

Performance

Competitor BTC-5021

Ther

mal

Per

form

ance TC-5022

Competitor A

10-15% Improvement at

lower price

Price

Comparable Performance at

Lower Price


TC-5021 Dispensable/Printable Silicone Grease

• Economic Version• Excellent Wetting Characteristics• Thermal Resistance = 0.16 cm2C/W• Stable and Reliable Performance

Room Temperature StorageSamples now available


TC-5022 Dispensable/Printable Silicon Grease

• Low Thermal Resistance = 0.069 cm2C /W• Excellent Wetting Characteristics• Optimized Filler Technology• Thin Bond Line at Low Pressures • Pressure Independent• No Pump Out, No Bleed Out

Room Temp StorageSamples now available

23.83.850.06923//100,000GreaseTC-5022

kW/mkc-cm2/Wumcp

Dielectric Constant@1kHz

Thermal Conductivity

Thermal ResistanceBLTCure

ViscositySystemProduct


Critical Thermal Grease Properties

21 cc

TIM

TIM RRk

BLTR ++=

Effective thermal resistance of a device, RTIM.

• BLT = Bond Line Thickness• kTIM = Thermal Conductivity• Rc = Contact Resistance between the TIM and the two surfaces.

Key Goal Minimize RTIM• Increase TIM thermal conductivity (kTIM).• Reduce Bond Line Thickness (BLT).• Reduce contact resistances (Rc) .


TIM Technology Development

Thermal Resistance

Bond Line ThicknessFiller Technology

Process-abilityReliability


Primary Components of Thermal Greases:• Filler:

– Size– Type – Loading

• Polymer:– Filler dispersion– Filler compatibility– Silicones

• Temperature Stability• Low Surface Energy

Thermal Grease Design Considerations

TIM Thermal conductivity (kTIM)Line Thickness (BLT)

Wetting, viscosity and maximum loadingHandling and processing


Measurement of Thermal Resistance by Guarded Hot Plate at Dow Corning

Heat Flux

Boundary condition control

Thermal sensor array

Boundary condition control

Thermal sensor array

Thermally conductivematerial

Weight

2.5mm

10mm

Heater Axis Cooler Axis

Calculate T.R. fromdifference of Temp.

Tem

pera

ture

Sample SurfaceHeater

Cooler

Test Condition: 50C, with 1cm X 1cm surface


TC-5021 Thermal Resistance vs. Pressure


Thermal Resistance Benchmark


OS-30 Impact


TC-5021 ReliabilityThermal Cycle

• Thermal reliability is an important aspect of TIM performance.• Steady thermal resistance indicates a good thermal reliability.



Screen Printing


Manual Screen Printer


Screen ThicknessEmulsion ThicknessPaste ViscositySqueegee PressureSqueegee SpeedScreen Gap

Thickness

Important Screen Printing Parameters

Substrate

Gap

Aluminum Frame

Screen

SqueegeePressure Angle HardnessSpeed

Screen ThicknessEmulsion Thickness


Effect of the Screen Thickness

a. Types of screen material: PET or Nylon or stainless steelb. Screen thickness is decided by the thread diameter (nomenclature:

S, T, HD) c. Generally, the smaller the mesh number, the thicker the mesh.

Therefore, under the same printing condition, using a small meshnumber screen can get a thick printed film


Squeegee Angle and Pressure

45o

Suggested start angleToo steepGood for

high viscosity grease

Should keep CONSTANT pressure, angle, and speed when pass through the patterned area



Effects of the Squeegee Hardness

80

70

60

Hardness

(45o squeegee but 30o at tip)

TC-5021


Screen Gap

Depend on the screen tension General speaking, 1~ 3 mm


Screen Gap (cont’d)

When the squeegee travels over the screen, the screen peel away immediately behind the squeegee


Screen Gap (cont’d)- Printing Defect

Insufficient gap causes grease separates from screen difficultly

If the screen gap is too big, a high pressure is needed for printing


Printing Deviation (cont’d)

The pad-to-pad weight difference can be controlled within 5%

g

0.44

0.45

0.46

0.47

0.48

0.49

0.5

0.51

0.52

0.53

80 mesh, 34x34 mm2 pad sizeSqueegee Blade Hardness = 70Screen Gap = 1.2mm

1 2 3 4 5 6 Group of Printing

TC-5021


Single-pass vs. Multi-pass

Pad-to-pad variation

*assume density = 3.4


Printing Defect

Overflow Backside Contamination

Cleaning backside of the screen periodically


Summary

• Suggest starting with 80 mesh screen, hardness 70 squeegee, 1~3 mm screen gap, and 45o squeegee angle

• Less than 5% pad-to-pad variation can be achieved by optimizing the printer parameters


Evaluating Thermal Grease


How Customers Evaluate Thermal Greases

• System Level– System fans combined

with ducting and venting

• Component Level–Active heat sink –Passive heat sink


Thermal Specifications

• Thermal Design Power (W)

• Maximum T case (oC) • Internal Chassis

temperature – < 38oC (Intel, 90nm)– < 45oC (Intel, 0.13um)

CPU TDPFMB 1.0 S478 Willemette, Northwood Core P4 89WFMB 1.5 S478 Prescott Core P4 103WFMB 2.0 LGA 775 P4 & P5 115W


Thermal Resistance Measurement

θca = θcs+ θsa = (Tc – TA)/PDwhere:θca = Thermal resistance from case to local ambient (oC /W)TC = Processor case temperature TA = Local ambient temperature in chassis around processor (oC)PD = Process power dissipation


Example

Thermal Test Vehicle (TTV) thermal coupler


What I should question about

Socket

Fan

different BLT ?compare with?

same heatsink?variable speed fan?

thermal coupler position?

Others?well printed pad ?

grease mixed well?Intel/AMD?

TDP (Power)?dummy die/TTV?


Do you know what they are?

PCI

PCI Express

Chipset

Socket

VoltageRegulator

PCI Express x 16

DIMM Socket


测试☺

• 5021&5022 不同?• 印刷网的目数？

• 印刷的压力和角度？

• 印刷刮刀硬度？

• OS-30的加入对性能影响？最多加多少？

• 每次印刷误差范围？

• 单次印刷还是多次印刷？

• 解释含义：21 cc

TIM

TIM RRk

BLTR ++=

TC-5021 & TC-5022 Product and Application Trainingcasmoon.com/upfile/file/20141020/2014102020293784551.pdf · Dow Corning . . . We Help You Invent The Future.™ TC-5021 & TC-5022

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